package com.idroid.utils.CacheTool;

import java.io.File;
import java.io.FileInputStream;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.HashMap;
import java.util.Map;

/**
 * MD5加密
 */
public class MD5Util {

    public static String getMD5(String str) {
        byte[] bytes;
        try {
            bytes = MessageDigest.getInstance("MD5").digest(str.getBytes("UTF-8"));
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("Huh, MD5 should be supported?", e);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("Huh, UTF-8 should be supported?", e);
        }

        StringBuilder sb = new StringBuilder(bytes.length * 2);
        for (byte b : bytes) {
            if ((b & 0xFF) < 0x10) sb.append("0");
            sb.append(Integer.toHexString(b & 0xFF));
        }
        return sb.toString();
    }

    //获取单个文件的MD5值！
    public static String getFileMD5(File file) {
        if (!file.isFile()) {
            return null;
        }
        MessageDigest digest = null;
        FileInputStream in = null;
        byte buffer[] = new byte[1024];
        int len;
        try {
            digest = MessageDigest.getInstance("MD5");
            in = new FileInputStream(file);
            while ((len = in.read(buffer, 0, 1024)) != -1) {
                digest.update(buffer, 0, len);
            }
            in.close();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        BigInteger bigInt = new BigInteger(1, digest.digest());
        //return bigInt.toString(16);
        return bigInt.toString(16);
    }

    //获取文件夹中文件的MD5值
    public static Map getDirMD5(File file, boolean listChild) {
        if (!file.isDirectory()) {
            return null;
        }
        Map map = new HashMap();
        String md5;
        File files[] = file.listFiles();
        for (int i = 0; i < files.length; i++) {
            File f = files[i];
            if (f.isDirectory() && listChild) {
                map.putAll(getDirMD5(f, listChild));
            } else {
                md5 = getFileMD5(f);
                if (md5 != null) {
                    map.put(f.getPath(), md5);
                }
            }
        }
        return map;
    }

    /**
     * 将String转成MD5
     *
     * @param string
     * @return
     * @throws Exception
     */
    public static String encode(String string) throws Exception {
        byte[] hash = MessageDigest.getInstance("MD5").digest(
                string.getBytes("UTF-8"));
        StringBuilder hex = new StringBuilder(hash.length * 2);
        for (byte b : hash) {
            if ((b & 0xFF) < 0x10) {
                hex.append("0");
            }
            hex.append(Integer.toHexString(b & 0xFF));
        }
        return hex.toString();
    }
}
